The remains of Julióbriga, Cantabria’s most significant Roman town, lie 4km east of Reinosa. Hourly guided visits (45 minutes, in Spanish) lead you through the Museo Domus, a full-scale recreation of one of Julióbriga's houses. You’re free to explore the excavated parts of the town (about 10% of the total), with a 12th-century Romanesque church built over the Roman forum, independently.
Julióbriga
Cantabria